Be sure it's something you *really* want to do, because hosting your own mail server isn't for the weak of heart. It takes a lot of effort to maintain, opens you up to numerous vulnerabilities, almost guarantees all your mail will be regarded as spam by Google / Microsoft, etc.
THIS IS EXACTLY WHAT I WAS WAITING FOR!
The social network of the future: No ads, no corporate surveillance, ethical design, and decentralization! Own your data with Mastodon!